The ability to attend to and use information accurately is very important and impairments of attention is indexed by conditioned stimulus processing profoundly disrupt an individual's life. These observations motivate research to understand the brain mechanisms involved in normal attentional processing, and the types of lifespan developmental changes that produce dysfunctions of conditioned stimulus processing and the ability to increment and decrement attention to auditory and visual cues. At the same time it is of critical importance to understand the early developmental stages that brain and behavior processes go through in terms of defining cognitive function in later life. Previous work in rats, monkeys, and humans has demonstrated that modification of frontal and temporal lobe structures, particularly the hippocampus and frontal cortex, produce behavioral changes that have some of the basic characteristics of an amnesic syndrome with associated dysfunctions in executive processes. The purpose of the present proposal is to extend our recent findings that indicate the potential for organization changes in brain structure that subserve conditioned stimulus processing by exposing the developing neurons system to different quantities of choline or folate; two nutrients shown to be critical to brain development. Previous research has shown that perinatal choline or folate supplementation leads to relatively permanent changes in the spatial ability of rats treated during specified periods (embryonic days 12-17 and postnatal days 15-30). The behavioral changes have been interpreted as reflecting an increase in memory capacity and precision. One of the major goals of our proposed research is to determine the role that attentional mechanisms play in behavioral facilitation and to determine if there are any negative consequences of these treatments that might be revealed by the recruitment of normal aging processes. In this regard, we will investigate the three possibilities that perinatal choline/folate supplementation/deficiency either have a) a positive effect on conditioned stimulus processing as a function of aging, b) a neutral effect on conditioned stimulus processing as a function of aging, or c) a negative effect on conditioned stimulus processing as a function of aging. These behavioral data will stimulate additional studies of the anatomical and neurochemical basis of the effects of aging on attention and memory.